Abstract: A group of 83 adolescents with attention deficit hyperactivity disorder (ADHD) were subdivided into those with ADHD alone (n = 27) and those with ADHD and oppositional defiant disorder (ADHD/ODD, n = 56). They were compared to each other and a community control group (n = 77) on measures of family conflicts, family beliefs, maternal adjustment, and observations of mother-adolescent interactions during both a neutral and conflict discussion. Both ADHD groups had more topics on which there was conflict and more angry conflicts at home than control adolescents on parent reports. Only the ADHD/ODD adolescents reported more such conflicts, endorsed more extreme and unreasonable beliefs about their parent-teen relations, and demonstrated greater negative interactions during a neutral discussion than the control teenagers. Similarly, only mothers of the ADHD/ODD teens displayed greater negative interactions during a neutral discussion, more extreme and unreasonable beliefs about their parent-teen relations, greater personal distress, and less satisfaction in their marriages than the mothers in the control group. Most findings for the ADHD only group were between the control group and the group with mixed ADHDIODD but did not differ from either group. Results imply that it is the combination of ODD symptoms with those of ADHD that is associated with the greater-than-normal conflicts, anger, poor communications, unreasonable beliefs, and negative interactive styles seen in ADHD adolescents. These same characteristics typify their mothers' interactions as well such that both the adolescents' ODD symptoms and maternal psychological distress (hostility) make unique contributions to the degree of conflict and anger in the parent-teen relations of ADHD adolescents.